From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Slaby Subject: Re: [PATCH] fbcon: Disable accelerated scrolling Date: Thu, 29 Oct 2020 06:42:39 +0100 Message-ID: <997267e5-40c1-2aaf-235a-ff14f2d101e6@kernel.org> References: <20201028160600.3752105-1-daniel.vetter@ffwll.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20201028160600.3752105-1-daniel.vetter-/w4YWyX8dFk@public.gmane.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Sender: "Nouveau" To: Daniel Vetter , DRI Development Cc: Bartlomiej Zolnierkiewicz , Tetsuo Handa , nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, "Gustavo A. R. Silva" , Peter Rosin , George Kennedy , Tomi Valkeinen , Ben Skeggs , Greg Kroah-Hartman , Daniel Vetter , Nathan Chancellor , Linus Torvalds , Peilin Ye List-Id: nouveau.vger.kernel.org On 28. 10. 20, 17:06, Daniel Vetter wrote: > So ever since syzbot discovered fbcon, we have solid proof that it's > full of bugs. And often the solution is to just delete code and remove > features, e.g. 50145474f6ef ("fbcon: remove soft scrollback code"). ... > --- a/drivers/video/fbdev/core/fbcon.c > +++ b/drivers/video/fbdev/core/fbcon.c > @@ -1147,11 +1147,13 @@ static void fbcon_init(struct vc_data *vc, int init) > > ops->graphics = 0; > > - if ((cap & FBINFO_HWACCEL_COPYAREA) && > - !(cap & FBINFO_HWACCEL_DISABLED)) > - p->scrollmode = SCROLL_MOVE; > - else /* default to something safe */ > - p->scrollmode = SCROLL_REDRAW; > + /* > + * No more hw acceleration for fbcon. > + * > + * FIXME: Garabge collect all the now dead code after sufficient time If you go this non-invasive path, then only a nit here: "Garbage" thanks, -- js suse labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.4 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98609C4363A for ; Thu, 29 Oct 2020 05:42:46 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3886D20704 for ; Thu, 29 Oct 2020 05:42:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3886D20704 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 070716E5C6; Thu, 29 Oct 2020 05:42:45 +0000 (UTC) Received: from mail-ej1-f65.google.com (mail-ej1-f65.google.com [209.85.218.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id A363B6E5C6; Thu, 29 Oct 2020 05:42:43 +0000 (UTC) Received: by mail-ej1-f65.google.com with SMTP id s15so2130985ejf.8; Wed, 28 Oct 2020 22:42:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=+zwvXGGP7Jimw9hLxGRvlejwQWtm5slzhppTkFSUgrc=; b=WbKSErVuGINgwsUDsevjbskrR0bSgOXC883odHRey+2/Qdy9DJZXr+39F8s16FMGfk ZZwQMHirjCYJRv0Y6OV87CPs6YQ/MfYuq3h/jQbxYg428P2CoWqhTxWk32HKTWXzsaBu EThAmmiDmnqWr7ULAX2NYJhIC4zI4o12dPYtcsmxD5Too5tLvODIfE85CtNxgIU8NRt4 9zz1KwmunnZ61m6jFxP5kdAYcQMV229KkhuRi6DagQSLNY2QnfEaUpOYjK5CtyJw6f9V /eOL4Hob9W0xMXb6bE4Eo+A9xdVuvseaUdoF5aAj6fwgSUdSNsRKjT4BTvKGmM7OpC3b KOkg== X-Gm-Message-State: AOAM530F5l3h7OwWCYsP4sNynGkcIGaJJlN9WkJMsHnmpTGhUenj2vio YdgRHcXbjcljXR9NwlMceXw= X-Google-Smtp-Source: ABdhPJw5i2GtoHk0Z+/903xc3/UHEIgOGT7HU6IhTnJrybfyZcqMoiA/N78eBzz/0tY3oFIdhSNfSA== X-Received: by 2002:a17:906:ce5c:: with SMTP id se28mr2290239ejb.365.1603950162313; Wed, 28 Oct 2020 22:42:42 -0700 (PDT) Received: from ?IPv6:2a0b:e7c0:0:107::49? ([2a0b:e7c0:0:107::49]) by smtp.gmail.com with ESMTPSA id m19sm840452eda.72.2020.10.28.22.42.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 28 Oct 2020 22:42:41 -0700 (PDT) Subject: Re: [PATCH] fbcon: Disable accelerated scrolling To: Daniel Vetter , DRI Development References: <20201028160600.3752105-1-daniel.vetter@ffwll.ch> From: Jiri Slaby Message-ID: <997267e5-40c1-2aaf-235a-ff14f2d101e6@kernel.org> Date: Thu, 29 Oct 2020 06:42:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.3 MIME-Version: 1.0 In-Reply-To: <20201028160600.3752105-1-daniel.vetter@ffwll.ch> Content-Language: en-US X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Bartlomiej Zolnierkiewicz , Tetsuo Handa , nouveau@lists.freedesktop.org, "Gustavo A. R. Silva" , Peter Rosin , George Kennedy , Tomi Valkeinen , Ben Skeggs , Greg Kroah-Hartman , Daniel Vetter , Nathan Chancellor , Linus Torvalds , Peilin Ye Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 28. 10. 20, 17:06, Daniel Vetter wrote: > So ever since syzbot discovered fbcon, we have solid proof that it's > full of bugs. And often the solution is to just delete code and remove > features, e.g. 50145474f6ef ("fbcon: remove soft scrollback code"). ... > --- a/drivers/video/fbdev/core/fbcon.c > +++ b/drivers/video/fbdev/core/fbcon.c > @@ -1147,11 +1147,13 @@ static void fbcon_init(struct vc_data *vc, int init) > > ops->graphics = 0; > > - if ((cap & FBINFO_HWACCEL_COPYAREA) && > - !(cap & FBINFO_HWACCEL_DISABLED)) > - p->scrollmode = SCROLL_MOVE; > - else /* default to something safe */ > - p->scrollmode = SCROLL_REDRAW; > + /* > + * No more hw acceleration for fbcon. > + * > + * FIXME: Garabge collect all the now dead code after sufficient time If you go this non-invasive path, then only a nit here: "Garbage" thanks, -- js suse labs _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel